I have a new (2002) coupe and have been filling the gas tank (topping-off) whenever it got down to 3/4 full. It now has 1500 miles on it and I took a trip and allowed the fuel gage to get down to 1/4 full. Now when I go to start the car - tank is still 1/4 full - it cranks and will not start until I try a second crank, at which time it finally starts. Could I be now using gas that has been in there since last winter? Thanks for any info.
Skipshift

 

Yes, the fuel is use from both tanks at the same time... The reasoning is to balance the car perfectly at all times.


[Modified by chuckster, 9:29 PM 4/16/2002]

 

skipshift,

#1 welcome to the forum!! :yesnod: :cheers: :cool:

#2 Hi, neighbor! I've lived in St. Charles most of my life but have been down the road a little for the past 2 years or so.

#3 thanks for your post, I totally did not know the C5 had 2 tanks :eek:

#4 My dad once had a car that he kept topping off the tank on and it eventually caused a problem with the tank float.

#5 Question: why top off the tank so much?

 

The left tank feeds the motor.As the level drops in the left tank,fuel is transfered from the right tank to the left tank.If you fill the tanks and you still have the problem (I am sure that you will),let me know and I will tell you what the problem is ;)

 

Hey C5 Tech can you enlighten us both, sometimes I have this problem as well. Not often though. Thanks

Lane

 

C-5 Tech:

1) tell us what the problem is, and:
2) how does the fuel gauge read the two tanks to give an indicated reading - perhaps this is the cause of the screwy gas gauge performance of so many of our cars??
3) is there a way to keep more fuel in the right tank to balance the car on the track with only a driver (and left seat) in the car?

 

Not to rain on anyones parade, but.....I just read an article in Corvette Fever from an "contact" in GM and they said, "...the computer is looking for the left tank to be full anytime there is fuel in the right tank. It is also looking for the fuel level to be changing as the car drives down the road. Once the righthand tank is empty (half tank on the fuel gauge) the computer is looking for the righthand signal to stay empty."

So, if this is true, then I would say Skipshift may be correct. If the gas in the left tank is 5 or 6 months old, it could have "gone bad". The hard thing to remember is, since there are two tanks, you should probably run the car down to 1/4 or less often. This contradicts everything I've been told about "running on empty" for over 20 years.

C-5 Tech, if this info is wrong, then I am sorry, but this is in the May 2002 issue, and then CF needs to be contacted.

 

Yep, I read that article too.

C'mon C5-Tech, don't leave us in the dark.

Roger

 

I have a question as well:

If I put a bottle of ocatane booster in my car, what tank does it dump into? Will it eventually get evenly distributed to both tanks and mix properly??

 

:confused: ???

 

So many questions,so little time ;) The filler neck goes to the left tank.When you fill up,when the left tank is full,fuel is than deposited to the right tank through a 2" crossover pipe.The left and right fuel senders are monitored by the PCM and the voltage imput to the PCM from both senders is how the gauge is controlled.As the level in the left tank (the one that feeds the motor) goes down,fuel is transfered from the right to left tank via a siphion jet pump in the right tank.Having replaced many fuel senders (which require draining the tanks) I can assure you that the tanks are always close to the same level ;)

To answer skipshifts question;If he is always topping off the tank,he is putting fresh fuel in the right tank,and that fuel is constantly being transfered to the left tank.The result would be equal quality fuel in both tanks,and I dont think fuel quality has anything to do with his hard or extended crank situation.

In his case,more than likely the fuel rail is not maintaining fuel pressure.This means that the fuel is either bleeding past an injector,or bleeding back into the left tank.If the injector is faulty,you will have a rough idle and smoke out the tailpipe upon start up.If fuel draining back into the tank is the culprit,there is a one way check valve in the fuel feed pipe off the left tank which prevents fuel drain back.If this valve is stuck,you will have extended crank time before starting due to lack of fuel up at the fuel injectors.The only way to correct this is to replace the fuel feed pipe (fuel line) on the left tank :yesnod:

 

When added,it will go into the left tank...Because of a return line to the right tank,it will eventually be evenly distributed :yesnod:

 

I think you have a valid answer to skipshifts problem. But the fuel tank thing?
I'm not saying who's right or wrong, but how can two "techs" have two different answers on how the fuel tanks feed? :crazy: Oh well, I guess that's why I going to buy an extended warranty :D

 

C-5 TECH is the man. :cheers:

I am surprised one of these tuners on here have not placed a called and offered you a nice relocation package. :lol: I feel good knowing that if my car needs some work, I am driving it to your dealer for service.